In this worksheet you will learn how the outputs of
the Picaxe chip control the buggy.

You'll also learn
2 ways of setting the outputs

1) Start up the PICAXE Programming Editor
program:
click here
- Make sure that PICAXE-18x is selected (in View / Options...)
- you should see the flowchart page. (if not, Click New / New flowchart or use the
button)

2) Enter the following flowchart
in Programming Editor:

This program sets Output 0 to ON.
If you want to set other Outputs instead,
use:,
or
etc. etc.

3) Download the program
to the buggy:
- connect up the download lead to the socket at the back of the buggy.
- switch on the buggy,
- Click on PICAXE/Run or click the
button. (or use F5)

The PIC chip is now running the program.
Check to see what the buggy is doing.

4) The PicAxe chip has
8 outputs. They are numbered from 0 to 7. Find out what they do.

Fill out the following table
by running all 8 different versions of the above program:

Output

Function

0

1

2

3

4

5

6

7

When You've worked out which outputs
control the Motors and LEDs, fill in the "Buggy Outputs" section of your Buggy Journal.

So far you've used
the PICAXE Programming Editor program in its Flowchart mode.

5) Now switch to Basic
(use the button)

This is your basic program:

'start of loop ---doletpins=%00000001
'end of loop -----loop

This program sets the Outputs to %00000001

If you want to set other patterns for the Outputs instead,
use:let pins=%00000100 ,
or let pins=%00001000
etc. etc.

6) Find out what the different patterns of
outputs do.

Fill out the
following table by running the above program with all 8 different patterns:

Let
pins=

Function

%00000001

%00000010

%00000100

%00001000

%00010000

%00100000

%01000000

%10000000

7) Binary Numbers.

Numbers such as "%10000000"
are
Binary numbers.

Its value depends on
the positions where the 1s are found. Position 0 is on the right hand end.

Binary numbers can be converted to denary (your normal numbers to the
base 10)
by using the following table.

Bit position

7

6

5

4

3

2

1

0

Denary value

128

64

32

16

8

4

2

1

For example:let pins = % 00001000

Bit position

7

6

5

4

3

2

1

0

Bit
Value

0

0

0

0

1

0

0

0

Denary value

128

64

32

16

8

4

2

1

When Bit 3 is 1 (in binary) it is worth 8 in denary

So let pins=%00001000 is equal to:
let pins = 8

The % means the number after it is binary.

Click on the three right hand digits of the binary number for a live display:

8) Now fill in the following table:

Buggy Movement

Binary

Denary

Forward

Let pins=%

Let pins=

Reverse

Let pins=%

Let pins=

Spin left

Let pins=%

Let pins=

Spin right

Let pins=%

Let pins=

Turn left

Let pins=%

Let pins=

Turn right

Let pins=%

Let pins=

When You've worked out the
patterns for forwards, spin, turn etc, fill in the
"Output Patterns" section of your Buggy Journal.

Hint: you add
together the separate patterns for the left and right motors.